Saito gas conversion – carb experience – page 6 – rccanada – canada radio controlled hobby forum gas tax in ct

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Lots of engines are designed for all sorts of different mixes so I don’t understand your question ,I have a NGH 38 that is designed to run 40:1 but it has bearings in the rod , all my 4 cycles with bearings run 40:1 and the bushing versions gas 4 cycles run 20:1 , and I have a few of them . My point was a engine with bushings designed for 20% oil on glow fuel will not fair well with 2%or50:1 oil on gas . Yes Rotary carbs and slide carbs a VV ,these carbs keep the air velocity more constant over the main jet . a butterfly carb needs to run on the low speed circuit until it transitions on to the main jet , so the air velocity over the main jet changes with RPM on the butterfly carb ,that is why they have problems leaning out at different points in the RPM range and are most often used on engines that run at a constant speed ( chain saws / weed wackers). They simply do not transition well when you get to small engines with very little air flow. I would say much under 50CC you should consider VV because it’s far superior at mixing fuel on small engines . hope this helps cheers Roger

Nice looking plane ,good job. I think you have proven your oil choice and mix is correct due to the years of service . Many guys don’t understand that oil does more then lubricate, it also cools ,seals and cushions . So while it is very important of have good quality oil, that is not the only factor, it needs to be in the correct amounts. simply having better lubricant does not always mean you can have less of it . If you don’t have sufficient oil the piston skirt will rock the rings will move in the ring lands and the rod will have more clearance on the crank pin ,and this is just a few thing that could suffer . these tolerances are very critical and designed with a measured amount of oil in mind to take up clearance when you increase these clearances by reducing oil you are asking for trouble . Reducing oil also reduces the engines ability to be able to remove heat from these very critical areas as the oil is also used for heat transfer . then you get into sealing and on and on . anyway great to hear your saito is Running so strong, they really are amazing engines . Hopefully I can get mine back into something this year . cheers Roger

Lots of engines are designed for all sorts of different mixes so I don’t understand your question ,I have a NGH 38 that is designed to run 40:1 but it has bearings in the rod , all my 4 cycles with bearings run 40:1 and the bushing versions gas 4 cycles run 20:1 , and I have a few of them . My point was a engine with bushings designed for 20% oil on glow fuel will not fair well with 2%or50:1 oil on gas . Yes Rotary carbs and slide carbs a VV ,these carbs keep the air velocity more constant over the main jet . a butterfly carb needs to run on the low speed circuit until it transitions on to the main jet , so the air velocity over the main jet changes with RPM on the butterfly carb ,that is why they have problems leaning out at different points in the RPM range and are most often used on engines that run at a constant speed ( chain saws / weed wackers). They simply do not transition well when you get to small engines with very little air flow. I would say much under 50CC you should consider VV because it’s far superior at mixing fuel on small engines . hope this helps cheers Roger

Nice looking plane ,good job. I think you have proven your oil choice and mix is correct due to the years of service . Many guys don’t understand that oil does more then lubricate, it also cools ,seals and cushions . So while it is very important of have good quality oil, that is not the only factor, it needs to be in the correct amounts. simply having better lubricant does not always mean you can have less of it . If you don’t have sufficient oil the piston skirt will rock the rings will move in the ring lands and the rod will have more clearance on the crank pin ,and this is just a few thing that could suffer . these tolerances are very critical and designed with a measured amount of oil in mind to take up clearance when you increase these clearances by reducing oil you are asking for trouble . Reducing oil also reduces the engines ability to be able to remove heat from these very critical areas as the oil is also used for heat transfer . then you get into sealing and on and on . anyway great to hear your saito is Running so strong, they really are amazing engines . Hopefully I can get mine back into something this year . cheers Roger